Despite considerable evidence of widespread neuropathology in the brains of people who have chronically abused alcohol, there is lack of agreement on the precise nature of consequent neuropsychological dysfunction. The proposed research will attempt to elucidate a limited number of possible perceptual and cognitive deficits in alcoholics with and without Korsakoff's syndrome, and to explore the suggestion that any observed impairments may have as an underlying factor, premature aging of the central nervous system. The experimental paradigms outlined in the proposed studies are derived from the existing literature on perceptual processing in normals, lateral specialization of hemispheric function in older normal and brain-damaged subjects, and recent findings relating to the effects of alcohol use and abuse on neuropsychological functioning. Models of perception and cognition have considered information processing in terms of a continuum of different depths or levels of analysis, within which the cerebral hemispheres tend to specialize in their relative abilities to analyze, categorize and store incoming stimulus information. One set of proposed studies will determine whether or not these functional asymmetries are differentially affected by long-term chronic alcoholism and by the presence or absence of clinical signs of Korsakoff's syndrome, and whether or not any observed deficits are more pronounced in older than younger alcoholics with similar drinking histories. Another set of proposed studies will employ experimental paradigms of proven value for measuring other types of functional breakdown following brain damage. These tasks include measures of cross-modal facilitation, temporal discrimination ability, selective attention and processing-time requirements, and memory for cues and for reward. In all of the proposed studies, data obtained on alcoholic Korsakoff patients and on non-Korsakoff alcoholics will be used to assess the possibility of a continuum of impairments (which may interact with age). Data obtained from control patients with focal brain damage will provide valuable information about lateralized functions and cognitive abilities of these groups, as well as comparisons for the effects of brain damage per se.